ETHNIC-DIFFERENCES IN NIFEDIPINE KINETICS - COMPARISONS BETWEEN NIGERIANS, CAUCASIANS AND SOUTH ASIANS

Nifedipine was administered to 12 healthy Nigerian volunteers as a sin gle oral dose of 20 mg capsule under fasting conditions. The pharmacok inetic results were compared with published data using the same protoc ol and analytical method for 27 Caucasians and 30 South Asians. The ar ea under the plasma concentration-time curve (AUC) of nifedipine in Ni gerians (808+/-250 ng ml(-1) h) was significantly higher (P<0.001) tha n that in Caucasians (323+/-116 ng ml(-1) h) and the difference remain ed significant (P<0.001) when corrected for body weight. The eliminati on half-life was also significantly higher (P<0.01) in Nigerians (5.03 +/-1.96 h) than in Caucasians (2.78+/-1.11 h). No significant differen ces were observed between Nigerians and South Asians in either AUC or half-life of nifedipine. The AUC of the nitropyridine metabolite was h igher (P<0.01) in Nigerians (220+/-51 ng ml(-1) h) compared with that in Caucasians (154+/-56 ng ml(-1) h) but the difference was not mainta ined when corrected for body weight. The AUC corrected for body weight and the elimination half-life of the metabolite were significantly hi gher in South Asians compared with those of Nigerians and Caucasians. The pharmacokinetics of oral nifedipine in Nigerians were similar to t hose in South Asians and therefore may also arise from a lower systemi c clearance compared with Caucasians as has been reported previously f or South Asians.